IAL   21557
INSTITUTO DE AGROBIOTECNOLOGIA DEL LITORAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
New pathways regulating Medicago truncatula root architecture
Autor/es:
O FRUGIER F, PLET J, ARIEL F, BOUALEM A, LAFFONT C, LAPORTE P, JOVANOVIC M, NAYA L, CHAN R, SALLET E, GOUZY J, HARTMANN C, LELANDAIS C AND CRESPI M
Lugar:
Gant, Bélgica
Reunión:
Conferencia; 8th European Nitrogen Fixation Conference; 2008
Institución organizadora:
Ghent University
Resumen:
Legumes are characterized by their ability to
develop two lateral organs from primary roots depending on environmental
conditions, lateral roots (common to all plants) and nitrogen-fixing nodules.
Physiological and genetic data indicate that development of these organs is
coordinated and involves common regulatory pathways, including phytohormonal
controls.
Recently, cytokinin signalling mediated by the
receptor MtCRE1 has been identified as crucial for both organogeneses in
the Medicago truncatula model legume (1). We characterized symbiotic and
non-symbiotic root phenotypes of M. truncatula mutants affected in
cytokinin signalling genes, obtained through the TILLING platform developed in
the frame of the Grain Legumes EEC project (GLIP; C. LeSignor and R. Thompson,
INRA-Dijon; D. Baker and J. Clarke, JIC-Norwich). This coupled with
transcriptomic approaches allowed us the identification of new cross-talk
elements between nodulation and cytokinin signalling pathways.
Regulation of transcript stability mediated by
microRNAs has been associated to various plant developmental processes. We notably
showed that MtmiR166 regulation, which targets type III HD ZIP
transcription factors, is crucial for patterning of root vascular bundles, and
formation of both lateral roots and nodules. Parallel analysis of small RNA
libraries from M. truncatula roots and nodules is being done to extend
our knowledge on the role of miRNA-mediated riboregulation in symbiotic
interactions.
Altogether, we characterized several new
pathways integrating symbiotic and non-symbiotic root architectures in legumes.
(1) Gonzalez-Rizzo
S., Crespi M. and Frugier F. The Medicago truncatula CRE1 cytokinin receptor
regulates lateral root development and early symbiotic interaction with Sinorhizobium
meliloti. (2006) Plant Cell 18, 2680-2693.